Fabrication of Chemotaxis Microfluidic Device Mould Using Digital Light Processing 3D Printing Method

Abstract

Chemotaxis microfluidic devices are one type of lab-on-a-chip (LOC) devices that functions to minimize the volume of sample used and the testing time by conducting an analysis on a smaller scale. Chemotaxis microfluidic devices consist of micro-scale features that are delicate to be produced using conventional manufacturing methods. Chemotaxis microfluidic devices are generally manufactured using soft lithography. This study attempts to apply hot embossing process to replace soft lithography process, in which the hot embossing mould was fabricated using 3D printing, especially digital light processing (DLP) methods. This project investigates the challenges of fabricating the hot embossing mould of chemotaxis microfluidic device using DLP 3D printing. Three printed orientations for the moulds were produced and compared. The three moulds are subsequently used in the hot embossing process to produce chemotaxis microfluidic devices on poly(methyl methacrylate) (PMMA) substrate. The performance of the moulds is compared to the mould produced by micro-milling process using qualitative (visual analysis) and quantitative (dimensional analysis) methods. The analysis shows that DLP 3D printed moulds have comparable quality with those produced by micro-milling. The printing orientation has significant effect on the dimensional differences between the mould and design with mould WT (area of width and thickness attached to the platform) has the smallest dimensional differences.